Pen-gesei



Reissued Apr. 14,1925.

UNITED STATES PA N v -'I CE- ADOLF DULIIZ. OF HIRSCHBERG, GERMANY, ASSIGNOR TO FLA K A FLAS C HEN-KAP- PEN-GESELLSCHAFT, 'M. B. 1-1.. OE BERLIN-CHARLOTTENBURG, GERMANY, A COR- PORATION or GERMANY.

SEALING CAP AND PROCESS FOR THE MANUFACTURE THEREOF.

No Drawing. Original No. 1 ,52( ),0 54, dated December 23, 1924, Application for reissue filed March 5, 1925.

To all whom it may concern:

- its strength,

be stripped from the former withoutbeing portance to reduce Be it known that I, AnoLr DULITZ, a citizen of Germany, and residing at Steinstrasse, Hirschberg, Silesia, Germanyypat entee of United States Patent No. 1,520,05at of December;23, 1924, herewithsurrendered, have invented certain new and Improved Sealing Caps and. Processes for. the Mannfact-nre Thereof, for which I filed an application in Germany on NovemberQS, 1922, and of which the following is a. specification.

Dry tightly fitting capsules made of acetyl cellulose and a Water soluble softening agent have already been proposed, which have been used by drawing the dry elastic pellicle on to the vessel to be closed and then immersing it in water. An exchange of soften ing agents and water thereupontakes place, so that after drying the pellicle. is caused to lie closely against the vessel ,to be sealed.

Owing to the manner in which they are made and used, the pellicles cannot have less than a certain minimum thickness and necessitate the use of a corresponding amount of raw material. This raw materialis however very expensii e and it is of great imthe quantity used as far as possible. y

This is effected by the exchange of softening agent and Water being caused to take place not after the pellicle. has been placed in position on the vessel to be sealed, but on the glass former, on which it is made.

- When the correct softening agents are chosen, a changetakes place. in the swelling of the pellicle by treating the pellicle on the glass former with water, on the softening agent being exchanged for water and the two having a certain proportion to one an-. other, which changeso alters its mass and that quite thin pellicles may damaged. This behavior makes it possible for the pellicle made from the acetyl cellulose solution mixed with the softening agent to have only a fraction of the thickness that would be required, if it were stripped in the soft state from the glass former without previoustreatment with water. The saving in the very expensive acetyl cellulose and its homologues thus ell'ected is very consider- Serial No, 711,247, filed May 5, 1924. -Seri.a1 No. 13,378.

able and results in the cost of the new capsules. being o-nly a fraction of that of the capsules made accordingto German Patent 364,397.. The capsules made according to the present method are sufliciently durable when in a moist state, maybe dyed in exactlythc same manner as those made by the older method or may be mixed with metallic powders. According to the present invention only those softening agents are suitable, which whendissolved out on the glass former leave the acetyl cellulose in a swelled state, but which do not precipitate. Asuitable softening agent is for instance the acetin referred to inGerma-n Patent 364,- 39'Z, but unsuitable agents are phenols and substituted phenols, which would alone or mixed with water act as solvents of acetyl cellulose and wouldnot allowof a swelled, sufficiently mechanically strong pellicle being formed. The so-called chloroform-soluthenew material for the new capsule capable of being mixed with metallic powder, as the substance before the treatment with water must be a swelled acetyl cellulose free from solvent.

The water-containing, moist pellicles made according to the present invention are so strong that they can be readily drawn on to the vessel to be sealed. On drying they then shrink to such an extent that-a perfectly tight sealing of the vessel is ensured.

"Wet pellicles of viscose have also been proposed, which are placed on the vessels to be sealed and are stated to make a tight seal on becoming dry. These known viscose. capsules can however not be made in the way described above and therefore entail the use of a correspondingly greater amount of raw material. Theyare also less durable'in the moist state, easily become ll'lOUltlY and must therefore always be treated with special preservatives. Lack of proper care on the part of the user may easily result in their being completely destroyed and becoming useless. 1

These disadvantages are entirely overcome when using the acetyl cellulose suggested above. The use of acetyl cellulose has the further great advantage for-the particular purpose of the manufacture of bottle capsules and similar seals,that dye stuffsof any kind can be. added to them, when in solution, which makes it possible to make. capsules having two or more colors, which have completely the character of metal. Printing of any kind may be made on these capsules, so that they provide the best possible protection against the contents of the bottles being exchanged and therefore the best trade mark protection.

I claim:

1. A. process for obtaining a sealing cover consisting in mixing with acetyl cellulose a water-soluble softening agent, forming therefrom a pellicle on a former and treatting the pellicle while on the former with water, for the purpose of causing an exchange of the softening agent for water to take place and of causing only a slight swelling of the pellicle.

2. Process for obtaining a sealing cap which consists in mixing with acetyl cellulose a water soluble softening agent of such character that by itself alone it does not act as a solvent of acetyl cellulose, producing from said miixture'a pellicle on the surface of a shaped instrumentality, treating the pellicle while on the said instrumentality with water for the purpose of causing an exchange of the'softening agent for Water to take place. andof causing only a slight swelling of the pellicle, strip ing the thus made pellicle "from the sha et instrumentality on which it was mace, and

I preserving it in moist condition until application to the vessel to be sealed thereby.

3. An acetyl cellulose sealing cap adapted to be applied to a containerand, on dry-. ing, to cause sealing thereof, said cap being substantially free from water soluble substances, but containing water which has replaced such substances, the cap having an acetyl cellulose content materially less than that of an acetyl cellulose cap made from a mixture of acetyl cellulose and a water soluble agent and dried.

4. An acetyl cellulose sealing cap adapted to be applied to acontainer and, on drying, to cause sea-ling thereof, said cap being substantially free from Water soluble substances, but containing water which has replaced such substances, having the characteristics of and being a product such as is obtained by mixing a water soluble softening agent with acetyl cellulose, producing from this mixture a pellicle on a shaped instrumentality, and treating the pellicle while on said instrumentality with water for the purpose of causing an exchange of the softening agent for water to take place.

Sealing means for containers consisting of a moist .pellicle composed of acetyl cellulose and water, the water being pres.- entas water of replacementremaining after an exchange, while the pellicle was on its shaping inst-rumentality as a mixture of acetyl cellulose and a water soluble softening agent, between said softening agentand said water. y f

In testimony whereof I have hereunto set my hand.

ADOL'F DULITZ. 

